Anchoring devices have been used in medicine for a number of years. Simple filament sutures (stitches) are used to hold one segment of tissue to another. With the advent of modern medicine, other types of anchors began to be used. To avoid the time required to sew up a wound and tie the sutures, rapid stapling procedures were developed. In the latter procedure, a form of staple is inserted into the tissue in lieu of a sewn stitch to hold the tissue segments together.
In 1977, Kronenthal et al received a patent (U.S. Pat. No. 4,006,747) on a new type of surgical fastening system. The system involves the partial insertion of "H"-shaped fasteners through the tissue adjacent an incision using a hollow needle and a push-rod. Once in place, an end of the fastener is located on each side of the incision and a filament that connects the two ends of the fastener consequently spans the incision. The fastener maintains the tissue in place thereby facilitating the natural healing process.
The "H" shaped fastener is also being used in a number of non-medically related fastening systems. This type of fastener is commonly used in stores to affix price tickets to clothing. A number of method are employed to install the fasteners in clothing. Two patents (U.S. Pat. Nos. 3,103,666 and 3,910,281) have been issued to A. R. Bone for hand held devices that aid in the insertion of this type of fastener into clothing.
In recent years, a modification of the fastening system has become prevalent in surgical procedures. Ogiu et al (U.S. Pat. No. 4,235,238), teaches a system wherein a "T" shaped fastener insertion needle is located within the end of an endoscope. Ogiu et al makes use of a hollow needle that has a longitudinally extending cavity sized to receive the head of the fastener. Once the needle has passed through the tissue on both sides of the wound, an obturator is pushed through the interior of the needle to dislodge the head of the fastener. The needle is then removed and an outer filament end of the fastener is tied to a lock member to maintain the closure of the wound.
Richards et al (U.S. Pat. No. 4,669,474) shows a similar system that makes use of a "T" shaped fastener. Richards et al implants the head of the fastener into the tissue using a hollow needle and push-rod (obturator). The head of the fastener is shaped so that it strongly anchors itself to the tissue and therefore provides a secure fastening point within the body. The filament end of the fastener is then secured exterior to the skin using a shaped retainer.
Mueller et al (U.S. Pat. No. 4,705,040) teaches a system that uses a "T" shaped fastener to anchor a hollow organ to the skin. In Mueller et al, a hollow needle and obturator are again used to implant the head of the fastener. However, Mueller et al places the head of the fastener within the interior cavity of the organ to be anchored. Mueller et al then makes use of a movable lock member to secure the outer filament end of the fastener to the exterior of the skin.
The presently used method and apparatus for inserting and placing "T"-shaped or "H"-shaped fasteners suffers from a number of deficiencies. Firstly, most of the prior art insertion needles have an open tip through which the head of the fastener is ejected. The hole in the needle's tip can catch and tear on the body tissue as the needle is pushed into the body. This can lead to a slower healing process and also possibly an increased chance of later infection. Secondly, when the obturator is pushed through the needle to eject the fastener, the doctor pushes on the obturator along its longitudinal axis while trying to hold the needle in place. Since this direction of force is also along the longitudinal axis of the hollow needle and the obturator is in contact with the needle, it is extremely difficult to eject the fastener without also moving the hollow needle. It is extremely easy to overcompensate for this inward force and accidentally pull the needle slightly outwards during the fastener ejection process. Thirdly, the insertion apparatus requires a significant amount of time to effect each fastener insertion. All of the above noted deficiencies combine to reduce the effectiveness and convenience of using "H"-shaped or "T"-shaped fasteners.